1. Field of the Invention
The present invention relates to a tilt hinge suitable for use in friction-rotatably coupling a keyboard main body being a first member and a display device being a second member of small OA equipment, for example, a laptop personal computer and a notebook personal computer.
2. Description of the Related Art
A laptop personal computer or a notebook personal computer is composed of a keyboard main body and a display device openably/closably attached to the keyboard main body via a tilt hinge. Such a personal computer is folded into two in not use while in use, the display device is opened for use relative to the keyboard main body. The thickness and size as small as possible are demanded for these computers, and accordingly, a tilt hinge with a small diameter and a high friction function is demanded. As a tilt hinge satisfying such demands, one described in Translated National Publication of Patent Application No. 2000-501149 is known.
A friction hinge described in this patent document is structured such that a plurality of clips in a washer shape each having a pair of arms, which are stacked in an axial direction are attached to a support means with rotation thereof being restrained, and a shaft is inserted between the respective arms to be in pressure contact with the arms, thereby generating a friction torque in a radial direction between an outer periphery of the shaft and the arms.
In the above-described friction hinge with a known structure, the pair of arms of each of the clips in a washer shape sandwich the shaft, thereby generating the friction torque. Therefore, it has a problem of a need for a large number of the clips in order to obtain a necessary friction torque with a small diameter because the friction area of each of the clips is small. In order to obtain a friction torque satisfying a development demand, for example, a friction torque of 100 kg/mm with a shaft with approximately 7 f, a larger number of the clips are required, which poses a problem of an increased axial dimension of the friction hinge.